Re: [kaffe] InputStream#available() for System.in throws IOException
From: Ito Kazumitsu <[EMAIL PROTECTED]> Subject: Re: [kaffe] InputStream#available() for System.in throws IOException Date: Tue, 30 Aug 2005 13:57:07 +0900 (JST) > So here is my proposed patch. I am checking this in. ___ kaffe mailing list kaffe@kaffe.org http://kaffe.org/cgi-bin/mailman/listinfo/kaffe
Re: [kaffe] InputStream#available() for System.in throws IOException
From: Ito Kazumitsu <[EMAIL PROTECTED]>
Subject: [kaffe] InputStream#available() for System.in throws IOException
Date: Tue, 30 Aug 2005 01:54:52 +0900 (JST)
> Case 1: Terminal input
> $ kaffe TestBufferedReader
>
> java.io.IOException: No such file or directory
> Case 2: Pipe
> $ echo | kaffe TestBufferedReader
> java.io.IOException: No such file or directory
> Case 3: File input - OK
> $ kaffe TestBufferedReader Case 4: Here document - OK
> $ kaffe TestBufferedReader < >
> > EOF
The message text of the IOException is meaningless.
This IOException comes from the macro TARGET_NATIVE_FILE_AVAILABLE
defined in libraries/clib/target/Linux/target_native_file.h.
If the standard input is piped to another process or it is a
character device, KFSTAT(filedescriptor,&__statBuffer) returns 0
but S_ISREG(__statBuffer.st_mode) is false because it is not a
regular file.
The solution may be either
(a) if S_ISREG(__statBuffer.st_mode) is false, try other
methods as libraries/clib/nio/FileChannelImpl.c did before.
or
(b) if S_ISREG(__statBuffer.st_mode) is false, give up trying
to figure out available length and just return 0.
I think (b) is simple and reasonable enough. Running the following
program on Sun's JDK,
public class TestAvailable {
public static void main(String[] args) throws Exception {
System.out.println(System.in.available());
}
}
I find Sun's System.in.available() often returns 0 if the standerd
input is a terminal or is piped to another process.
So here is my proposed patch.
--- libraries/clib/target/Linux/target_native_file.h.orig Fri Aug 5
10:20:19 2005
+++ libraries/clib/target/Linux/target_native_file.hTue Aug 30 13:31:24 2005
@@ -138,18 +138,26 @@
\
length=0; \
\
-if ((KFSTAT(filedescriptor,&__statBuffer)==0) &&
S_ISREG(__statBuffer.st_mode)) \
+if (KFSTAT(filedescriptor,&__statBuffer)==0) \
{ \
- int klseek_result; \
- klseek_result=(KLSEEK(filedescriptor,0,SEEK_CUR, &__n)); \
- if (klseek_result == 0) \
+ if (S_ISREG(__statBuffer.st_mode)) \
{ \
-
length=TARGET_NATIVE_MATH_INT_INT32_TO_INT64(__statBuffer.st_size-__n); \
-result=TARGET_NATIVE_OK; \
+int klseek_result; \
+klseek_result=(KLSEEK(filedescriptor,0,SEEK_CUR, &__n)); \
+if (klseek_result == 0) \
+{ \
+
length=TARGET_NATIVE_MATH_INT_INT32_TO_INT64(__statBuffer.st_size-__n); \
+ result=TARGET_NATIVE_OK; \
+} \
+else \
+{ \
+ result=TARGET_NATIVE_ERROR; \
+} \
} \
else \
{ \
-result=TARGET_NATIVE_ERROR; \
+ length=TARGET_NATIVE_MATH_INT_INT32_TO_INT64(0); \
+ result=TARGET_NATIVE_OK; \
} \
} \
else \
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[kaffe] InputStream#available() for System.in throws IOException
Hi,
The program attached below throws java.io.IOException when run with
current CVS version of Kaffe.
Case 1: Terminal input
$ kaffe TestBufferedReader
java.io.IOException: No such file or directory
at gnu.java.nio.channels.FileChannelImpl.available (FileChannelImpl.java)
at java.io.FileInputStream.available (FileInputStream.java:165)
at java.io.FilterInputStream.available (FilterInputStream.java:129)
at java.io.BufferedInputStream.read (BufferedInputStream.java:276)
at java.io.FilterInputStream.read (FilterInputStream.java:173)
at java.io.InputStreamReader.read (InputStreamReader.java:395)
at java.io.BufferedReader.fill (BufferedReader.java:373)
at java.io.BufferedReader.readLine (BufferedReader.java:475)
at TestBufferedReader.main (TestBufferedReader.java:12)
java.io.IOException: No such file or directory
Case 2: Pipe
$ echo | kaffe TestBufferedReader
java.io.IOException: No such file or directory
at gnu.java.nio.channels.FileChannelImpl.available (FileChannelImpl.java)
at java.io.FileInputStream.available (FileInputStream.java:165)
at java.io.FilterInputStream.available (FilterInputStream.java:129)
at java.io.BufferedInputStream.read (BufferedInputStream.java:276)
at java.io.FilterInputStream.read (FilterInputStream.java:173)
at java.io.InputStreamReader.read (InputStreamReader.java:395)
at java.io.BufferedReader.fill (BufferedReader.java:373)
at java.io.BufferedReader.readLine (BufferedReader.java:475)
at TestBufferedReader.main (TestBufferedReader.java:12)
java.io.IOException: No such file or directory
Case 3: File input - OK
$ kaffe TestBufferedReader
> EOF
$
This error occurs on both FreeBSD and Linux.
Slight differences among operating systems are:
(1) On Linux 2.6.7-co-0.6.2, the message of the IOException is
"Success" instead of "No such file or directory".
(2) On Linux 2.4.18-3, instead of throwing IOException, the program
seems to go into a deadlock. But giving an argument to the
program, we see the same IOException.
$ echo | kaffe TestBufferedReader US-ASCII
java.io.IOException: No such file or directory
at gnu.java.nio.channels.FileChannelImpl.available (FileChannelImpl.java)
at java.io.FileInputStream.available (FileInputStream.java:165)
...
And here is the program for testing.
import java.io.*;
public class TestBufferedReader {
public static void main(String[] args) throws Exception {
try {
BufferedReader rdr = new BufferedReader(
(args.length > 0 ?
new InputStreamReader(System.in, args[0]) :
new InputStreamReader(System.in)));
while (true) {
String s = rdr.readLine();
if (s == null) break;
}
}
catch (Exception e) {
e.printStackTrace();
throw e;
}
}
}
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